1. Field of the Invention
The present invention relates to a piezoelectric motor, a stage equipped with the piezoelectric motor, and an electronic apparatus equipped with the piezoelectric motor.
2. Description of the Related Art
In recent years, as means for achieving ultraprecise positioning, attention has been given in various fields to the piezoelectric motor, also called an ultrasonic motor, for friction-driving a movable body contacting with a vibrating body having a piezoelectric element by vibration of the vibrating body. Especially, piezoelectric motor utilizing as a vibrating body a rectangular plate is widely used in various fields as a linear motor.
As a method of supporting the vibrating body in the form of a rectangular plate, as shown in FIG. 15, there is known a structure in which surroundings of rectangular plate vibrating bodies 100 comprising the piezoelectric elements are supported so as to be interposed by an elastic member 101 (for example, Patent Document 1).
[Patent Document 1]
Japanese Patent No. 2980541 Gazette (10–11 pages, FIG. 11)
However, in case where there is adopted the structure in which the vibrating bodies are supported by being interposed by means of the elastic member, there is such a case that the elastic member itself is deformed after positioning has been finished, so that a position of operation portion deviates. Further, also at a starting or stopping time, a support member is deformed by a reaction force, and a hysteresis in driving characteristic (moving quantity) has been liable to occur. Accordingly, as a result, the position of the movable body is liable to deviate, so that there has been a problem that it is difficult to realize the high precision positioning.
Further, there is an example in which vibrating bodies are supported by mutual engagement of members made of metal, for example, without using the elastic body, but also in this case there is a fear that the similar result is brought about in the engaging portion if there is a play.
Additionally, similarly to the support by the elastic body, if supporting conditions (constraint force, etc.) change, there has been a possibility that not only a dispersion in characteristic of an individual motor becomes large, but also the characteristic is greatly changed also by external environments (temperature, etc,).